[dba-VB] Visual Basic Question/Access

To all,
 
I created a VB6 application a while back, I added the Microsoft Access 10.0 Object Library so that I could import spreadsheets & text files using DoCmd.TransferText or DoCmd.TransferSpreadsheet commands.  All worked fine so I left it as it was, I have just gone to run it and I get the error message:
 
            This Operation Requires An Open Database.
 
I haven’t changed any code and it worked the last time I ran the application.  So I guess I need to know either why it may not be working now or how I can get it to work.  Or is there another way I can change this.
 
Thanks in advance for any help.
 
Paul Hartland